diff options
| author | Xiyu Yang <xiyuyang19@fudan.edu.cn> | 2021-11-09 03:34:48 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-09 19:02:51 +0100 |
| commit | 1077c2857791076a7e81b0ba91571f136cee08e4 (patch) | |
| tree | 219168759f7105f1b875d8330a56a20f71a1fbea /fs/coda | |
| parent | coda: avoid doing bad things on inode type changes during revalidation (diff) | |
| download | linux-1077c2857791076a7e81b0ba91571f136cee08e4.tar.xz linux-1077c2857791076a7e81b0ba91571f136cee08e4.zip | |
coda: convert from atomic_t to refcount_t on coda_vm_ops->refcnt
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.
Link: https://lkml.kernel.org/r/20210908140308.18491-8-jaharkes@cs.cmu.edu
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jing Yangyang <jing.yangyang@zte.com.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/coda')
| -rw-r--r-- | fs/coda/file.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/coda/file.c b/fs/coda/file.c index 52deab784667..29dd87be2fb8 100644 --- a/fs/coda/file.c +++ b/fs/coda/file.c @@ -8,6 +8,7 @@ * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. */ +#include <linux/refcount.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/time.h> @@ -28,7 +29,7 @@ #include "coda_int.h" struct coda_vm_ops { - atomic_t refcnt; + refcount_t refcnt; struct file *coda_file; const struct vm_operations_struct *host_vm_ops; struct vm_operations_struct vm_ops; @@ -98,7 +99,7 @@ coda_vm_open(struct vm_area_struct *vma) struct coda_vm_ops *cvm_ops = container_of(vma->vm_ops, struct coda_vm_ops, vm_ops); - atomic_inc(&cvm_ops->refcnt); + refcount_inc(&cvm_ops->refcnt); if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open) cvm_ops->host_vm_ops->open(vma); @@ -113,7 +114,7 @@ coda_vm_close(struct vm_area_struct *vma) if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close) cvm_ops->host_vm_ops->close(vma); - if (atomic_dec_and_test(&cvm_ops->refcnt)) { + if (refcount_dec_and_test(&cvm_ops->refcnt)) { vma->vm_ops = cvm_ops->host_vm_ops; fput(cvm_ops->coda_file); kfree(cvm_ops); @@ -189,7 +190,7 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) cvm_ops->vm_ops.open = coda_vm_open; cvm_ops->vm_ops.close = coda_vm_close; cvm_ops->coda_file = coda_file; - atomic_set(&cvm_ops->refcnt, 1); + refcount_set(&cvm_ops->refcnt, 1); vma->vm_ops = &cvm_ops->vm_ops; } |